1. Field of the Invention
The present invention relates to the design of arrow shafts such as used in the field of archery. All such arrow shafts are round and straight, have points of various types, nocks and fletching. Points are essentially for penetration either into targets or game. The nock of the arrow functions to engage the bow string until the arrow is loosed. The flight characteristics of the arrow depend primarily on the fletching, either made from feathers or plastic. The fletching causes a measurable drag on the arrow and may also become partially or wholly torn from the shaft of the arrow during use, further impairing the aerodynamics of the flight of the arrow, necessitating the repair or replacement of the fletching. Fletching usually consists of three vanes, each attached to the rear of the arrow shaft at about 120.degree. from the others so that when the bow string is in the nock, one vane is horizontal at 90.degree. to the nock and the other two vanes are about 30.degree. from vertical. This necessary placement of the vanes has an inherent slightly detrimental effect on aerodynamics. It would be advantageous to modify the shape of the shaft to improve the aerodynamics and accuracy for the conventional arrow with fletching or to eliminate the necessity for fletching.
2. Description of the Prior Art
The basic arrow consists of point, shaft, fletching and nock. The points have been made from bone, flint, and metal and vary in shape, depending upon their use at targets, fish or various game. Nocks were simply carved into the shaft of the arrow, but are now predominately plastic and replaceable. One such nock (U.S. Pat. No. 5,306,019 to Guest and Eckert) is adjustable and holds the bow string within the nock until release. Fletching is usually made from feathers, such as turkey, or plastic. Shafts have been made from reed, wood dowels, carbon fiber and metal tubes and have always been round and straight. Aerodynamics of the shaft have been improved through the addition of an airfoil structure on top of the shaft (U.S. Pat. No. 4,182,513 to Henderson).
There is a need for a more aerodynamic arrow shaft that will provide increased range, a flatter trajectory, improve accuracy and eliminate the need for fletching or airfoil structures.